BRITISH STANDARD AEROSPACE SERIES BS A 298 1988 ISO 8642 1986 Methods of test for Self locking nuts with maximum operating temperature greater than 425 °C [ISO title Aerospace — Self locking nuts with[.]
BRITISH STANDARD AEROSPAC E SERIES BS A 298:1 988 ISO 8642:1 986 Methods of test for Self-locking nuts with maximum operating temperature greater than 425 ° C [ISO title: Aerospace — Self-locking nuts with maximum operating temperature greater than 425 ° C — Test methods] UD C 62 : 62 882 : [62 882 4] : 62 – : 62 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS A 298:1988 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Aerospace Standards Committee (ACE/- ) to Technical Committee ACE/1 upon which the following bodies were represented: Civil Aviation Authority (Airworthiness Division) Electronic Engineering Association Ministry of Defence Society of British Aerospace Companies Limited This British Standard, having been prepared under the direction of the Aerospace Standards Committee, was published under the authority of the Board of BSI and comes into effect on 29 January 988 © BSI 01 - 2000 The following BSI references relate to the work on this standard: Committee reference ACE/1 Draft for comment 85/72371 DC ISBN 580 16382 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy Amendments issued since publication Amd No Date of issue Comments BS A 298:1988 Contents Page Committees responsible National foreword Inside front cover ii Scope and field of application References Inspections and tests Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure Figure Figure Figure Figure Figure 1 11 Figure 12 Table — Bolt dimensions for self- locking torque test at ambient temperature (single cycle test) Table — Test bolt coating in relation to the coating of the nut to be tested Table — Dimensions of the mandrels for permanent set test Publications referred to © BSI 01 - 2000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 10 Inside back cover i BS A 298:1 988 National foreword This British Standard, which has been prepared under the direction of the Aerospace Standards Committee, is identical with ISO 8642: 986 “Aerospace — Self-locking nuts with maximum operating temperature greater than 425 ° C — Test methods ” published by the International Organization for Standardization (ISO) Terminology and conventions The text of the International Standard has been approved as suitable for publication as a British Standard without deviation Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following The comma has been used as a decimal marker In British Standards it is current practice to use a full point on the baseline as the decimal marker Wherever the words “International Standard” appear referring to this standard, they should be read as “British Standard” C ross-references International Standard C orresponding British Standard BS 6293 ISO 5855- : 981 MJ threads for aerospace construction Specification for dimensions of basic profile Part : 982 (Identical) ISO 5855- 2: 981 Part 2: 982 nuts Specification for dimensions for bolts and (Identical) ISO 7403: 983 BS A 294: 984 configuration Specification for spline drive wrenching Metric series (Identical) The Technical Committee has reviewed the provisions of ISO 691 , ISO/R 024, ISO 6507- , ISO 6508 and ISO 8641 1) to which reference is made in the text, and has decided that they are acceptable for use in conj unction with this standard Related British Standards to some of the aforementioned International Standards are as follows: International Standard Related British Standard ISO 691 : 983 Specification for open-ended wrenches BS 41 75 Method for Rockwell superficial hardness test (N and T scales) Part : 967 Testing of metals Part 2: 970 Verification of the testing machine BS 427 Method for Vickers hardness test Part : 961 Testing of metals BS 891 Method for Rockwell hardness test Part : 962 Testing of metals ISO/R 024: 969 ISO 6507- : 982 ISO 6508: 986 BS 92: 982 A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application C ompliance with a British Standard does not of itself confer immunity from legal obligations Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages to 2, an inside back cover and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover 1) At present at stage of draft ii Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 01 - 2000 BS A 98: 988 S cop e and fie ld of ap p lication This International Standard specifies test methods for metric self- locking nuts with MJ threads the — Rockwell superficial hardness, in accordance with ISO/R 024; — microhardness 3) maximum operating temperature of which is It is strongly recommended to use the method greater than 425 °C, intended for use in aerospace corresponding to the hardness unit indicated construction It describes the test device and the Should this not be possible, the use of conversion method for each test Other test devices or test methods than those specified in this International Standard may be used, but, in the event of a dispute, the requirements laid down in this International Standard shall take precedence charts is allowed, but, given their inaccuracy, the results obtained shall be used warily In the event of a dispute, the results obtained using the method corresponding to the hardness unit indicated shall take precedence 3.1 Method This International Standard shall be used in This test shall be carried out at ambient conj unction with the procurement specification laid temperature down in ISO 8641 The measurement zone (bearing surface, across It applies to self- locking nuts as defined above, flats, underside of anchor nut lugs, etc ) shall provided that the relevant documents correspond to the following conditions: (drawing, procurement specification, etc ) refer to this International Standard Re fe re nce s Wrench and socket openings — Metric series — Tolerances for general use ISO 691 , Rockwell superficial hardness test (N and T scales) for steel ISO/R 024, Aerospace construction — MJ threads — Part : Basic profile ISO 5855- , a) thickness at least equal to times the penetration depth; b) deviation in parallelism with respect to bearing surface not greater than ° Should this not be possible, carry out this test on a cut section after moulding the nut into a resin capable of maintaining it in the correct position Remove all possible coating (protection, lubrication, paint, etc ) in the measurement zone True up the bearing surface to obtain the required relationship Aerospace — MJ threads — Part 2: Dimensions of bolts and nuts liable to modify the characteristics of the material Metallic materials — Hardness test — Vickers test — Part 1: HV to HV 00 Carry out the test and then check conformity with ISO 5855- 2, ISO 6507- , Metallic materials — Hardness test — Rockwell test (scales A — B — C — D — E — F — G — H — K) ISO 6508, Fasteners for aerospace construction — Spline drive wrenching configuration — Metric series ISO 7403, Aerospace — Self-locking nuts with maximum operating temperature greater than 425 ° C — Procurement specification2) ISO 8641 , Insp e ctions and te sts These two operations shall not generate any heat constituting the nut to be tested the requirements of the drawing NOTE Nuts subj ected to this test shall not be used again Be aring surface square ne ss te st 3.2.1 Test device The test device is illustrated in Figure The test device includes the following elements: a) a threaded mandrel with end in accordance with ISO 5855- and ISO 5855- 2, except for the pitch diameter which shall be in accordance with the values specified in Table for the maximum mandrel; H ard ne ss te st 3.1 Procedure The authorized procedures are as follows: — Rockwell hardness, in accordance with ISO 6508; — Vickers hardness, in accordance with ISO 6507- ; 2) 3) b) a collar sliding on the plain portion of the threaded mandrel the external diameter B of which shall be at least equal to reference dimension A for types I, III and VI nuts in Figure and equal to reference dimension A for types II, IV and V nuts in Figure 2; c) an appropriate feeler gauge At present at the stage of draft Will be dealt with in a future International Standard © BSI 01 - 2000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS A 98: 988 NO TE For shank nuts, the sliding collar shall have a counterb ore to accommodate the shank Figure 3.2.2 Method Figure The test shall be carried out at ambient temperature For floating nuts, extract the nut from the cage or Axial load te st 3.3.1 Test device The test device is illustrated in Figure The test device includes the following elements: channel a) a bearing plate in steel, heat- treated to Screw the threaded mandrel into the nut or threaded part until it engages with the self- locking zone Move the collar into contact with the bearing surface HRC W 40; b ) a bolt with a rolled thread and characteristics as follows: ) threads: in accordance with ISO 5855- and ISO 5855- , Evaluate the out- of- squareness by means of a feeler gauge the thickness of which shall correspond to the permissib le squareness error as laid down in the drawing or the procurement specification ) tensile strength classification: greater than that of the nut to be tested, 3) material: alloy steel, non- coated; c) a torque wrench Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 01 - 000 BS A 98: 988 3.3.2 Method 3.3.2.2 100 % test The axial load is transmitted to the nut by the bolt, This test shall be carried out at ambient the nut resting on the bearing plate temperature 3.3.2.1 If preliminary exposure to temperature is necessary 80 % test for the test, heat the nut and maintain it at the This test shall be carried out at ambient temperature stipulated in the procurement temperature Lubricate the bolt and nut threads with synthetic aero engine oil Assemble the bearing plate onto the bolt Assemble the nut and measure the locking torque, using the torque wrench, when the protrusion is pitches it to cool slowly to ambient temperature Then, in all cases, proceed as described below Lubricate the bolt and nut threads with synthetic aero engine oil Assemble the bearing plate onto the bolt; assemble the nut with a protrusion of pitches minimum (including chamfer) Position the assembly on the tensile machine Apply the load slowly and progressively in the direction shown in Figure Reduce the load slowly and minimum (including chamfer) Position the assembly on the tensile machine and apply the load slowly and progressively in the direction shown in Figure Reduce the load slowly progressively when the value stipulated in the and progressively when the value stipulated in the procurement specification has been reached procurement specification has been reached Remove the assembly from the tensile machine Remove the assembly from the tensile machine Unscrew the nut through half a turn and cease movement, then again unscrew and measure the breakaway torque; using the torque wrench Remove the nut, then submit it to a visual examination and, if necessary, to an examination under low magnification after sectioning to check Remove the nut, then submit it to a visual examination and, if necessary, to an examination under low magnification after sectioning to check conformity with the requirements of the specification; take the nut from the oven and allow conformity with the requirements of the procurement specification NOTE Nuts subj ected to this test shall not be used again procurement specification Figure © BSI 01 - 2000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS A 298:1 988 Repeat the operations described below the number 3.4 Wrenching feature test of times specified in the procurement specification This test applies only to wrenchable nuts 3.4.1 Test device The test device is illustrated in Figure Apply the torque to the nut, in a tightening movement, as stipulated in the procurement 4) The test device includes the following elements a) a block of steel, heat- treated to HRC specification, with the aid of the torque wrench 4) W 40; : Remove, then replace the socket wrench Apply the same torque to the nut in an untightening direction b) a bolt with a rolled thread and characteristics Finally, dismantle the assembly, then submit the as follows: nut to a visual examination and, if necessary, to an ) threads: in accordance with ISO 5855- and ISO 5855- 2, 2) tensile strength classification: no particular requirement, sectioning to check conformity with the requirements of the procurement specification NOTE Nuts subj ected to this test shall not be used again 3.5 Torque-out test 3) material: no particular requirement; This test applies only to nuts made from more than c) a torque wrench, having a socket with an one part, either by design (floating anchor nuts or opening tolerance conforming to ISO 691 for gang channel nuts) or for manufacturing purposes hexagonal and bihexagonal wrenching or (fixed anchor nuts the threaded element of which is ISO 7403 for spline wrenching 3.4.2 examination under low magnification after Method assembled to the baseplate by brazing or clinching) It aims to check that the retention device is able to This test shall be carried out at ambient resist rotation of the threaded portion during temperature tightening and untightening Make two flats on the flange of the nut so that it has a clearance of 0, 05 to 0, mm inside the slot, lubricate the bolt and nut threads with synthetic aero engine oil Insert the modified nut into the slot Assemble the bolt and moderately tighten it, then assemble the block into a vice Figure 4) It is also possible to carry out this test with nuts welded on a block of the same material, the assembly being heat treated to the correct level Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 01 - 2000 BS A 298:1 988 3.5 Test device Assemble the locknut and apply the same torque in the reverse direction using the same procedure The test device is illustrated in Figure Dismantle the assembly, then submit the threaded element as well as the base- plate, the cage or the channel to a visual examination and, if necessary, to an examination under low magnification after sectioning to check conformity with the requirements of the procurement specification NOTE Nuts subj ected to this test shall not be used again 3.6 Push-out test This test applies only to gang channel nuts and anchor nuts with the exception of corner nuts shown in Figure and reduced series single lug nuts D A B –0, 05 3, 5 10 6 8 14 14 14 3, 3, 4, 5, 6, 7, 8, 0, Figure The test device includes the following elements: 3.6.1 Test device Figure The test device is illustrated in Figure a) a fixing plate; b) a shouldered mandrel threaded in accordance with ISO 5855- and ISO 5855- 5) ; c) a locknut threaded in accordance with ISO 5855- and ISO 5855- 2; d) rivets with universal heads or bolts with cylindrical heads and hexagonal nuts to fix the nut or the portion of the channel to be tested (standardized aerospace fasteners); e) a torque wrench 3.5 Method This test shall be carried out at ambient temperature Attach the nut or portion of the channel to be tested on the plate by means of rivets or bolts and nuts, the preformed heads of rivets or the heads of bolts being located on the same side as the element to be tested Lubricate the mandrel and nut threads with synthetic aero engine oil Screw in the mandrel so that the shoulder contacts the threaded element of the nut (on bearing surface or bottom of counterbore) Apply the torque to the nut, in a tightening movement, as stipulated in the procurement specification, using the torque wrench 5) D A B –0, 05 3, 5 10 6 8 14 14 14 3, 3, 4, 5, 6, 7, 8, 0, Figure A shouldered sleeve mounted on a bolt may also be used © BSI 01 - 2000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS A 298:1 988 The test device includes the following elements: 3.7 Self-locking torque at ambient a) a fixing plate; temperature b) a push rod with spherical end; 3.7.1 c) a bolt with a rolled thread and characteristics The test device is illustrated in Figure Test device as follows: ) thread: in accordance with ISO 5855- and ISO 5855- 2, 2) tensile strength classification: no particular requirement, 3) material: no particular requirement; d) rivets with universal heads or bolts with cylindrical heads and hexagonal nuts to fix the nut or the portion of the channel to be tested (standardized aerospace fasteners) 3.6.2 Method This test shall be carried out at ambient temperature Attach the nut or the portion of the channel to be Figure tested onto the plate by means of rivets or bolts and nuts, the preformed heads of rivets or the heads of bolts being located on the same side as the element to be tested Apply the axial load stipulated in the procurement specification using the rod with the spherical end Using an appropriate feeler gauge, ensure that any permanent deformation is not greater than the value stipulated in the procurement specification The test device includes the following elements: a) a steel spacer, heat- treated to HRC W 40 (this may be a cylindrical sleeve or a block with parallel faces pierced with a series of holes) 6) ; b) a bolt with a rolled thread and characteristics as follows: For the single cycle test: Try to screw a standard bolt manually into the nut, ) thread: in accordance with ISO 5855- even if deformed, as far as the locking device and ISO 5855- 2, except for the pitch Dismantle, then subj ect the nut as well as the cage and the channel to a visual examination and, if diameter the minimum and maximum dimensions of which are given in Table , necessary, to an examination under low 2) tensile strength classification: greater magnification after sectioning to check conformity than or equal to that of the nut to be tested, with the requirements of the procurement specification NOTE Nuts subj ected to this test shall not be used again 3) material: alloy steel, non- coated, For the multiple cycle test: ) thread: in accordance with ISO 5855- and ISO 5855- 2, 2) material: identical to that of the nut to be tested, 3) coating: in accordance with Table 2; c) a torque wrench 6) The same spacers as for the test described in 3.8 (see Figure 9) may be used Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 01 - 2000 BS A 298:1 988 Table — Bolt dimensions for Remove the load by unscrewing through half a turn self-locking torque test at ambient temperature (single cycle test) Dimensions in millimetres Pitch diameter Thread ( D × pitch a d) and cease movement Again unscrew and measure the breakaway torque, using the same procedure Dismantle the assembly, then submit the bolt and nut to a visual examination and, if necessary, to an examination under low magnification after sectioning to check conformity with the max b MJ3 × 0, 2, 627 2, 651 MJ3, × 0, 3, 057 3, 084 MJ4 × 0, 3, 489 3, 51 requirements of the procurement specification 3.7.2.2 Multiple cycle test Proceed as stated in 3.7.2.1 repeating the cycle on the same bolt the number of times stipulated in the MJ5 × 0, 4, 420 4, 450 procurement specification, and measure the MJ6 × 5, 279 5, 31 self- locking torque under the same conditions at the MJ7 × 6, 279 6, 31 first assembly and at each disassembly It is MJ8 × 7, 279 7, 31 mandatory that the first assembly be carried out on a new bolt Each disassembly shall be sufficient to MJ1 × , 25 9, 1 9, 51 MJ1 × , 25 1 , 03 1 , 46 MJ1 × , 2, 936 2, 981 MJ1 × , 4, 936 4, 981 MJ1 × , 6, 936 6, 981 disengage the nut locking device entirely NOTE Nuts subj ected to the multiple cycle test shall not be used again 3.8 Self-locking torque at ambient temperature after heat soak at maximum MJ20 × , 8, 936 8, 981 MJ22 × , 20, 936 20, 981 MJ24 × 22, 595 22, 648 3.8.1 operating temperature Test device MJ27 × 25, 595 25, 648 The test device is illustrated in Figure MJ30 × 28, 595 28, 648 The test device includes the following elements: MJ33 × 31 , 595 31 , 648 MJ36 × 34, 595 34, 648 MJ39 × 37, 595 37, 648 d specified in ISO 5855- for bolts with a tolerance class of 4h6h d2 + d2 max a b Values equal to Values equal to specified in ISO 5855- for the coating of the nut to be tested Test bolt coating tested diameter of the thread) or with a reduced shank (diameter of the plain portion equal to the pitch ) thread: in accordance with ISO 5855- and ISO 5855- 2, 2) material: identical to that of the nut to be tested, Silver or MoS None None Silver Method (diameter of the plain portion equal to the follows: Table — Test bolt coating in relation to 3.7.2 b) a bolt with a rolled thread and a normal shank diameter); the characteristics of the bolt are as bolts with a tolerance class of 4h6h Coating of the nut to be a) a spacer in material identical to that of the nut to be tested; 3) coating: in accordance with Table 2; c) a torque wrench This test shall be carried out at ambient temperature During the test, the nut temperature shall not exceed 45 ° C and the cycling shall not exceed 30 r/min 3.7.2.1 Single cycle test Lubricate the nut and bolt threads with synthetic aero engine oil, then assemble the nut to the bolt after having added the spacer Measure the self- locking torque, using the torque wrench, when the protrusion is pitches minimum (including chamfer) Apply the seating torque stipulated in the procurement specification © BSI 01 - 2000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS A 98: 988 L Thre ad D × pitch MJ3 × 0, MJ3, × 0, MJ4 × 0, MJ5 × 0, MJ6 × MJ7 × MJ8 × MJ1 × , 25 MJ1 × , 25 MJ1 × , B o lt le ngth S tre ss are a o f the b o lt thre ad 28 36 5, 439 28 36 7, 335 30 40 9, 51 30 42 5, 296 32 46 21 , 753 32 46 30, 930 32 48 41 , 682 32 52 65, 36 36 56 97, 28 36 60 31 , 562 Figure Method — for the Waspaloy (NiP 01 HT): B = 590 MPa This test shall be carried out at ambient — for the Inconel 71 (NiP 00 HT): temperature Lubricate the nut and bolt thread with synthetic aero engine oil, then assemble the nut to the bolt after having positioned the spacer Measure the self- locking torque, using the torque wrench, when L E B = 590 MPa is the length of the spacer, in millimetres; is the modulus of elasticity of the bolt: — for the A 286, (FE- PA 92 HT): E = 20, × the protrusion is pitches minimum (including chamfer) Tighten the nut so as to obtain an %L, as indicated in the MPa — for the Waspaloy (NiP 01 HT): formula given below (this measurement shall be E = 21 , × carried out with an accuracy of — for the Inconel 71 (NiP 00 HT): elongation of the bolt, ± 4m): M E = 20, × 4 MPa MPa is the length of the plain portion of the bolt shank (incomplete screw- threads not included); where B is the axial constraint to be applied to the stress area of the bolt thread specified in the table in Figure 9: — for the A 286, (FE- PA 92 HT) : Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy B = 520 MPa H d is the total height of the nut to be tested; is the maximum root diameter of the threaded part, in accordance with ISO 5855- 2; D is the actual diameter of the plain portion of the test bolt shank (measured on length M) © BSI 01 - 2000 BS A 98: 988 After submitting the assembly to load, leave it under tension at room temperature for at least h; measure the elongation again and, if necessary, readj ust it so as to obtain the desired preload (this measurement shall be carried out with an accuracy of ± 4m) Heat the assembly to the temperature and for the length of time stipulated in the procurement specification Remove the assembly from the oven and allow it to cool slowly to ambient temperature Remove the load by unscrewing through half a turn and cease movement Again unscrew and measure the breakaway torque, using the torque wrench Stop the motion again, clean the bolt threads protruding beyond the nut to remove the baked oil residue and lubricate it with synthetic aero engine oil so as to avoid abrasive damage to the nut Remove the nut Repeat the cycle the number of times stipulated in Method Figure the procurement specification, the bolt being This test shall be carried out at ambient cleaned and brushed after each removal, and temperature measure the self- locking torque at each cycle under Check that the mandrel dimensions are within the the same conditions limits given in Table and that their threads have Dismantle, then submit the bolt and nut to a visual not been damaged examination and, if necessary, to an examination Lubricate the nut thread and the maximum under low magnification after sectioning to check mandrel thread with synthetic aero engine oil; conformity with the requirements of the assemble the nut to the maximum mandrel and procurement specification measure the locking torque, using the torque NOTE Nuts subj ected to this test shall not be used again Pe rmane nt se t te st This test details the method for checking the possibility of reusing self- locking nuts on bolts the thread of which is at the tolerance limit 9.1 wrench, when the protrusion is pitches minimum (including chamfer); then unscrew the nut Test device Lubricate the nut thread and the minimum mandrel thread with synthetic aero engine oil; assemble the nut to the minimum mandrel with a protrusion of pitches minimum (including chamfer) ; then measure the breakaway torque, using the same The test device consists of procedure, in the unscrewing direction a) a maximum and a minimum threaded Remove the nut, then submit it to a visual mandrel, in conformity with Figure 0, the examination and, if necessary, to an examination characteristics of which are as follows: under low magnification after sectioning to check ) threads: in accordance with ISO 5855- and conformity with the requirements of the ISO 5855- 2, except for the pitch diameter and procurement specification tolerances which shall be in accordance with NOTE the values specified in Table 3, Vib ration te st 2) material: steel, heat- treated to HRC b) a torque wrench W 39; Nuts subj ected to this test shall not be used again Taking into account the capacity of vibration machines, this test applies only to nuts of diameter 5, 6, 7, 8, and mm 3.1 0.1 Test device The test device is illustrated in Figure 1 The test device includes the following elements: a) a parallelepiped block comprising oblong openings; b) spacers; © BSI 01 - 2000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS A 98: 988 c) washers; — flush off the skirt of shank nuts at the level of d) bolts with a rolled thread and normal shank the bearing surface (diameter of the plain portion equal to nominal If preliminary exposure to temperature is necessary thread diameter), having the following for the test, lubricate the nut and bolt threads with characteristics: synthetic aero engine oil; then assemble the nut to ) threads: in accordance with ISO 5855- and the bolt with a protrusion of pitches minimum ISO 5855- 2; (including chamfer) Heat the assembly to the 2) material: identical to that of the nut to be tested, temperature for a period of h ± Allow to 3) coating: in accordance with Table 2; cool slowly outside the oven to ambient temperature After cleaning the bolt threads e) a torque wrench protruding beyond the nut to remove the baked oil Each spacer is held captive in the block by the residue and after lubricating the nut with synthetic addition of the washer on the side opposite the shoulder, the two parts being assembled by the bolt and the nut to be tested, as shown in Figure 3.1 0.2 maximum operating temperature stated in the drawing of the nut, to ± ° C, and maintain at this Method aero engine oil so as to avoid abrasive damage to the nut, remove the nut Then, in all cases, proceed as described below Lubricate the bolt and nut threads with synthetic This test shall be carried out at ambient aero engine oil and assemble the nut to the bolt after temperature having positioned the spacer and the washer (the Certain types of nuts will require preparation in the nuts subj ected to preliminary exposure to following manner: temperature shall be assembled in the same bolts) — extract floating nuts from their cages or Apply the tightening torque, using the torque channels; wrench, stipulated in the procurement specification — saw the lugs from plate nuts symmetrically Untighten the nut and unscrew so as to completely about the axis; disengage the locking feature Tab le — D ime nsions of the mandre ls for p e rmane nt se t te st Dimensions in millimetres Pi tch d i ame te r ( d) To le rance s Thre ad D × pitch Maximum mandrel Maximum mandrel a On d of maximum and minimum On half angle On pitch mandrels MJ3 × 0, 2, 662 2, 627 MJ3, × 0, 3, 096 3, 057 MJ4 × 0, 3, 530 3, 489 MJ5 × 0, 4, 464 4, 420 MJ6 × 5, 333 5, 279 MJ7 × 6, 333 6, 279 MJ8 × 7, 332 7, 279 MJ1 × , 25 9, 69 9, 1 MJ1 × , 25 1 , 67 1 , 03 MJ1 × , 3, 003 2, 936 MJ1 × , 5, 002 4, 936 MJ1 × , 7, 001 6, 936 MJ20 × , 9, 000 8, 936 MJ22 × , 20, 999 20, 936 MJ24 × 22, 673 22, 595 MJ27 × 25, 672 25, 595 MJ30 × 28, 670 28, 595 MJ33 × 31 , 670 31 , 595 MJ36 × 34, 670 34, 595 MJ39 × 37, 670 37, 595 a Values equal to d ± 5½ ± 0, 008 whatever the –0, 01 pitch ± 0½ specified in ISO 5855- for bolts with a tolerance class of 4h6h 10 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 01 - 2000 BS A 298:1988 If a nut unscrews completely, stop the test, pick up the defective nut and the failed parts of the assembly, then continue the test on the other nuts for a period equal to that remaining At the end of the period, stop the test and remove the assembly from the vibration-generating equipment Examine the assemblies and any rotation of the nut relative to the bolt Finally, unscrew the nuts, then submit them to a visual examination and, if necessary, to an examination under low magnification after sectioning to check conformity with the requirements of the procurement specification Repeat the tighten/untighten cycle four times and then carry out a fifth tightening, still on the same bolt, after mounting the assembly in an opening in the block Mark a reference line over the end of the bolt onto the nut Lightly lubricate the friction surfaces with synthetic aero engine oil and check that the spacer moves freely within the opening Fix the assembly on the appropriate vibration-generating equipment having the following characteristics: — sinusoidal form; — frequency: 30 Hz; — total displacement: 11,43 ± 0,4 mm Submit the assembly to the appropriate vibratory regime for the period stipulated in the procurement specification The test device shall be positioned to obtain a vertical displacement Check throughout the test that the assembly moves freely within the openings Nominal thread diameter MJ5 MJ6 MJ7 MJ8 MJ10 MJ12 A +0,15 8,29 12,65 14,25 15,83 19,00 25,35 B +0,1 27,16 31,58 33,18 34,75 37,92 44,28 NOTE Nuts subjected to this test shall not be used again C +0,1 5,2 6,3 7,3 8,3 10,3 12,3 D –0,1 8,22 12,62 14,22 15,79 18,97 25,19 E –0,25 14,09 19,17 20,77 22,35 25,52 35,05 F –0,1 3,17 4,19 4,19 4,19 4,19 4,82 Figure 11 © BSI 01-2000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 11 BS A 298:1988 Figure 12 12 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 01 - 000 BS A 298:1988 Publications referred to See national foreword © BSI 01 - 000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS A 298:1988 ISO 8642:1986 BSI — British Standards Institution BS I is the indep endent national b ody res p ons ib le for p rep aring Britis h S tandards It p res ents the UK view on s tandards in E urop e and at the international level It is incorp orated b y Royal C harter Revisions Britis h S tandards are up dated b y amendment or revis ion Us ers of Britis h S tandards should make s ure that they p oss es s the latest amendments or editions It is the constant aim of BS I to imp rove the quality of our p roducts and services We would b e grateful if anyone finding an inaccuracy or amb iguity while us ing this Britis h S tandard would inform the S ecretary of the technical committee res p ons ib le, the identity of which can b e found on the inside front cover Tel: 02 89 96 90 00 Fax: 02 89 96 40 BS I offers memb ers an individual up dating s ervice called PLUS which ens ures that s ub s crib ers automatically receive the lates t editions of s tandards Buying standards O rders for all BS I, international and foreign s tandards p ub lications s hould b e addres s ed to C us tomer S ervices Tel: 899 00 Fax: 899 7001 In res p ons e to orders for international standards , it is BS I p olicy to sup p ly the BS I imp lementation of thos e that have b een p ub lis hed as Britis h S tandards, unless otherwis e requested Information on standards BS I p rovides a wide range of information on national, E urop ean and international standards through its Lib rary and its Technical H elp to E xp orters S ervice Various BS I electronic information s ervices are also availab le which give details on all its p roducts and s ervices C ontact the Information C entre Tel: 02 89 96 71 1 Fax: 02 89 96 048 S ub s crib ing memb ers of BS I are kep t up to date with s tandards develop ments and receive sub s tantial discounts on the p urchase p rice of s tandards For details of thes e and other b enefits contact Memb ership Adminis tration Tel: 02 89 96 70 02 Fax: 02 89 96 00 Copyright C op yright s ub s is ts in all BS I p ub lications BS I als o holds the cop yright, in the UK, of the p ub lications of the international s tandardization b odies E xcep t as p ermitted under the C op yright, D es igns and Patents Act 988 no extract may b e rep roduced, s tored in a retrieval s ystem or transmitted in any form or b y any means – electronic, p hotocop ying, recording or otherwis e – without p rior written p ermis s ion from BS I This does not p reclude the free us e, in the cours e of imp lementing the standard, of necess ary details such as s ymb ols, and size, typ e or grade designations If thes e details are to b e used for any other p urp os e than imp lementation then the p rior written p ermiss ion of BS I must b e ob tained If p ermis sion is granted, the terms may include royalty p ayments or a licensing agreement D etails and advice can b e ob tained from the C op yright Manager BS I 89 C his wick H igh Road London W4 4AL Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy Tel: 02 89 96 70